1. Technical Field
The present invention relates to movable chairs and platforms, and more particularly to exercise devices for moving selected parts of a human body sitting in the chair.
2. Background Art
A unique mechanism has been designed concisely and ingeniously. The chair may optionally use only one crankshaft to produce an aligned movement with three types of motion. They are the curvilinear-circular, swivel-rock, and vertical motions. These actions allow the body's waist, abdomen and buttocks to move just like the Hula Dance, (that is the reason it is called the Hula chair) which limbers up the whole body.
Schenck, U.S. Pat. No. 3,667,453, discloses a chair having a movable seat that reciprocates around a vertical axis relative to the chair for exercise purposes. Unlike the present invention with movement in all three axes, the Schenck chair moves the seat in a single two-dimensional plane.
Kost, U.S. Pat. No. 2,595,272, develops three dimensional movement in the seat using a crankshaft mounting to the seat support suspended above a ball joint. The movement is restricted in one dimension through the anchoring effect of the ball joint, unlike the present invention.
Stout, U.S. Pat. No. 1,733,919, is another chair with a seating portion or base that moves. The movement in the Stout device is caused by a "bent" crankshaft attached to the seat base. As the crankshaft is turned, the seat is moved in a three-dimensional "zigzag" pattern. The design does not control movement as disclosed in the present invention.
U.S. Pat. Nos. 3,374,782; 3,581,739; 3,865,430; 3,912,260; 3,923,300; 4,061,137; 4,369,969; 4,483,327; and, 4,509,743 disclose several other versions of movable chairs and other types of exercise machines. The movement in each is generally limited or the references do not disclose a chair.